ABC News(WASHINGTON) — During Tuesday’s White House meeting — already unusual for being open to cameras and the public — President Trump threw a curveball to the 20 lawmakers present when he brought up earmarks, the mere mention of which is pretty much banned along with the practice itself.

“I hear so much about earmarks and how there was a great friendliness when you had earmarks. Of course they had other problems, but maybe all of you should start thinking about going back to a form of earmarks,” the president told the assembled Democrats and Republicans.

Depending on the politician, the word “earmark” might evoke an easier, more collegial time of legislative deal-making, or a wasteful practice that should have never been so widely exercised.

But the baseline, commonly accepted definition of an earmark is pretty clear, as summed up by a 2006 Congressional Research Service study: funds set aside in spending bills for a specified program, project, activity, institution or location. These funds tend to benefit the state or district of the particular lawmaker seeking them, and may have nothing to do with the underlying bill itself.

And while Trump pledged during his campaign to “drain the swamp,” most fiscal conservatives and government watchdogs believe allowing earmarks would simply fill it back up.

“It’s the antithesis,” of Trump’s pledge, Rep. Dave Brat, R-Va., told ABC News. “The whole country wants to throw out the swamp, and that’s part of it.”

Earmarks tended to be for provincial projects such as infrastructure development or local municipal facilities. The most notorious example might be Alaska’s so-called “Bridge to Nowhere” project, the funds for which originally appeared in a 2004 transportation bill. It would have connected a remote part of Alaska to an airport but was never actually constructed.

And while used sporadically going back to the 18th century, earmarks became much more popular in the last 20 years. According to the Congressional Research Service, the number of earmarks in bills related to labor, health and human services and education alone rose from five in 1994 to 3,014 in 2005.

They typically had to do with securing the beneficiary’s support on something, whether on the bill in question or on other matters entirely. But the availability of earmarks also led to scandals including those of lobbyist Jack Abramoff, Rep. Duke Cunningham and others, in which lawmakers illegally directed funding that ended up benefiting clients or campaign donors.

Bolstered by anti-corruption public sentiment, House and Senate Republicans voted in 2010 to impose moratoriums on earmarking. President Barack Obama helped solidify the ban, announcing in his 2011 State of the Union address that he would veto any bill that came to his desk with earmarks attached.

“The American people deserve to know that special interests aren’t larding up legislation with pet projects,” Obama said at the time.

Sen. Jeff Flake, who as a then-House Republican led the charge to ban the practice, said the corruption that came with earmarking is part of what led Republicans to lose their majority in both houses of Congress in 2006.

“That’s the last thing we want to go back to,” he said.

But that doesn’t mean all lawmakers are opposed to bringing them back. Republican Sen. Lindsey Graham applauded the president at the meeting for floating the idea, telling reporters later that earmarks allow members of Congress to have more influence over how taxpayer dollars are allocated.

“Earmarks won’t fix all of our problems but having Congress back involved will help,” Graham said.

Rep. Pete Sessions, R-Texas, chairman of the House Rules Committee, plans to hold a hearing next week to discuss potentially reintroducing earmarks, but he didn’t sound enthusiastic about bringing earmarks back.

“We believe the president … wants to reengage in the process and evaluate and make recommendations about where it would go,” he told ABC. “As chairman of the committee, we are not moving backwards, and it would not be a recommendation for us to move back to almost any part of the system that I saw that existed 2011.”

The word “earmark” is a four-letter word among fiscal conservatives. But Tom Schatz, president of Citizens Against Government Waste, said that while the earmark ban helped curtail the practice, lawmakers are still using directed spending as a way to extract favors. But now, Schatz said, they have to allocate the funds generally to programs which might overwhelmingly benefit their state, rather than pinpoint the money to specific states or individual projects.

The annual CAGW “Pig Book,” which tracks what the group deems wasteful spending, names 163 examples of directed spending totaling $6.8 billion, that Congress approved in FY 2017. That’s much less than the record $29 billion the group says was spent on formal earmark projects in 2006, the year Republicans lost control of Congress, but it’s still an increase from the previous year, Schatz noted.

“They’ve just essentially created a definition that allows them to include these projects without calling them earmarks,” he said.